This invention relates to clutch assemblies for motor vehicles and more particularly to an electric actuator for such a clutch assembly.
Internal combustion engines require some manner of device to bridge the gap between fly wheel and gear box input speeds when the vehicle begins to move. Such devices, with the ability to slip in a controlled manner, have taken many forms including disk clutches and torque converters. The torque converter allows two-pedal driving and provides smooth operation. However, it exhibits constant slip even at high speed, with associated fuel economy disadvantages and necessitates the use of a hydraulic circuit with consequent power losses. The manual disk clutch, by contrast, is rugged and expensive and does not slip during normal operation but requires attention and effort on the driver's part. In an attempt to eliminate some of the driver effort associated with a manual clutch, various actuator devices have been proposed which operate in response to a driver shift signal to engage and disengage the clutch, thereby relieving the driver of the clutching and declutching effort. However, the prior art clutch actuators have either not effectively carried out the clutching and declutching operations, have been prohibitively expensive, or have required unacceptable levels of maintenance with associated warranty problems.